Image-based navigation has become popular. In one type of system, a computer displays to a user photographic images taken in a real-world locality. The user navigates through a representation of the depicted locality by changing his virtual location or by “turning his head.” The computer keeps up with the user's navigation and displays photographic images taken from the real-world locality that represent the user's current point of view. Thus, the user is given a virtual, visual tour of the real-world locality. One system for performing this kind of feature is disclosed in U.S. Pat. No. 7,688,229 , filed Apr. 30, 2007, the entire disclosure of which is incorporated by reference herein.
An image dataset often lies behind the navigation application. The images used for this application are collected by a set of one or more cameras carried through the locality. The camera may be mounted on a vehicle or carried by a person on foot. The cameras take pictures (or video) in all directions as the vehicle or person moves. Because numerous, overlapping pictures are taken from several points of view, the set of pictures can be post-processed to create seamless 360-degree images, as disclosed in U.S. Pat. No. 7,688,229. These images are correlated with real-world geography, for example by gathering GPS data at the same time as the pictures are taken.
Because the pictures are taken from public streets, they often include people, vehicles, and other transient objects that would be of no use to a user navigating through the virtual representation of the depicted locality. Furthermore, objects (e.g., trees) may obscure other objects (e.g., buildings). The presence of people in the pictures also raises privacy concerns when the people can be identified.